/* =========================================================
   Idiot Unit Converter Tools — Design System
   Palette: indigo core, slate neutrals, amber signature accent
   ========================================================= */

:root{
  --indigo-900:#1e1b4b;
  --indigo-700:#4338ca;
  --indigo-600:#4f46e5;
  --indigo-500:#6366f1;
  --indigo-100:#e0e7ff;
  --indigo-50:#eef2ff;

  --slate-950:#0b0f19;
  --slate-900:#0f172a;
  --slate-800:#1e293b;
  --slate-700:#334155;
  --slate-500:#64748b;
  --slate-300:#cbd5e1;
  --slate-200:#e2e8f0;
  --slate-100:#f1f5f9;
  --slate-50:#f8fafc;

  --amber-500:#f59e0b;
  --amber-400:#fbbf24;

  --green-600:#059669;
  --red-600:#dc2626;

  --font-display:'Manrope',system-ui,sans-serif;
  --font-body:'Inter',system-ui,-apple-system,sans-serif;
  --font-mono:'JetBrains Mono',ui-monospace,SFMono-Regular,Consolas,monospace;

  --radius-sm:8px;
  --radius-md:14px;
  --radius-lg:22px;
  --shadow-sm:0 1px 2px rgba(15,23,42,0.06);
  --shadow-md:0 8px 24px -8px rgba(30,27,75,0.18);
  --shadow-lg:0 20px 50px -12px rgba(30,27,75,0.25);
  --max-w:1180px;
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:var(--font-body);
  color:var(--slate-800);
  background:var(--slate-50);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
h1,h2,h3,h4{font-family:var(--font-display);color:var(--slate-900);line-height:1.2;margin:0 0 .5em;}
p{margin:0 0 1em;}
.container{max-width:var(--max-w);margin:0 auto;padding:0 24px;}
.mono{font-family:var(--font-mono);}

/* ---------- Skip link ---------- */
.skip-link{
  position:absolute;left:-9999px;top:0;background:var(--indigo-700);color:#fff;
  padding:10px 16px;z-index:200;border-radius:0 0 8px 0;
}
.skip-link:focus{left:0;}

/* ---------- Header ---------- */
.site-header{
  position:sticky;top:0;z-index:100;
  background:rgba(15,23,42,0.92);
  backdrop-filter:blur(10px);
  border-bottom:1px solid rgba(148,163,184,0.15);
}
.site-header .container{
  display:flex;align-items:center;justify-content:space-between;
  height:68px;gap:20px;
}
.brand{
  display:flex;align-items:center;gap:10px;font-family:var(--font-display);
  font-weight:800;font-size:1.15rem;color:#fff;white-space:nowrap;
}
.brand .brand-mark{
  width:34px;height:34px;border-radius:10px;
  background:linear-gradient(135deg,var(--indigo-500),var(--amber-500));
  display:flex;align-items:center;justify-content:center;font-size:1.1rem;
  box-shadow:var(--shadow-sm);
}
.brand small{display:block;font-family:var(--font-body);font-weight:500;font-size:.65rem;color:var(--slate-300);letter-spacing:.04em;}

.main-nav{display:flex;align-items:center;gap:22px;}
.main-nav a{color:var(--slate-200);font-size:.92rem;font-weight:600;transition:color .15s;}
.main-nav a:hover,.main-nav a:focus-visible{color:#fff;}

.header-search{position:relative;flex:1;max-width:320px;}
.header-search input{
  width:100%;padding:10px 14px 10px 38px;border-radius:999px;border:1px solid rgba(148,163,184,.3);
  background:rgba(255,255,255,.08);color:#fff;font-size:.88rem;font-family:var(--font-body);
}
.header-search input::placeholder{color:var(--slate-300);}
.header-search input:focus{outline:2px solid var(--amber-400);outline-offset:1px;background:rgba(255,255,255,.14);}
.header-search svg{position:absolute;left:12px;top:50%;transform:translateY(-50%);opacity:.6;pointer-events:none;}
.search-results{
  position:absolute;top:calc(100% + 8px);left:0;right:0;background:#fff;border-radius:var(--radius-md);
  box-shadow:var(--shadow-lg);border:1px solid var(--slate-200);overflow:hidden;display:none;max-height:340px;overflow-y:auto;z-index:150;
}
.search-results.open{display:block;}
.search-results a{display:flex;align-items:center;gap:10px;padding:10px 14px;font-size:.88rem;color:var(--slate-800);border-bottom:1px solid var(--slate-100);}
.search-results a:last-child{border-bottom:none;}
.search-results a:hover,.search-results a.active{background:var(--indigo-50);}
.search-results .none{padding:14px;color:var(--slate-500);font-size:.85rem;}
.nav-toggle{display:none;background:none;border:none;color:#fff;font-size:1.5rem;cursor:pointer;}

/* ---------- Hero ---------- */
.hero{
  background:
    radial-gradient(circle at 15% 20%,rgba(99,102,241,.35),transparent 45%),
    radial-gradient(circle at 85% 0%,rgba(245,158,11,.25),transparent 40%),
    linear-gradient(180deg,var(--slate-900),var(--indigo-900) 130%);
  color:#fff;padding:76px 0 90px;position:relative;overflow:hidden;
}
.hero .eyebrow{
  display:inline-flex;align-items:center;gap:8px;font-family:var(--font-mono);
  font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--amber-400);
  background:rgba(245,158,11,.1);border:1px solid rgba(245,158,11,.3);
  padding:6px 12px;border-radius:999px;margin-bottom:22px;
}
.hero h1{font-size:clamp(2.1rem,4.4vw,3.4rem);color:#fff;max-width:820px;letter-spacing:-.02em;}
.hero h1 .hl{
  background:linear-gradient(90deg,var(--amber-400),#fca5a5 60%,var(--indigo-500));
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero p.lead{font-size:1.12rem;color:var(--slate-300);max-width:640px;margin-bottom:32px;}
.hero-search{max-width:560px;position:relative;}
.hero-search input{
  width:100%;padding:18px 20px 18px 52px;border-radius:16px;border:1px solid rgba(255,255,255,.16);
  background:rgba(255,255,255,.07);color:#fff;font-size:1.02rem;
}
.hero-search input::placeholder{color:var(--slate-300);}
.hero-search input:focus{outline:2px solid var(--amber-400);}
.hero-search svg{position:absolute;left:18px;top:50%;transform:translateY(-50%);opacity:.7;}
.hero-search .search-results{top:calc(100% + 10px);}
.hero-stats{display:flex;gap:34px;margin-top:40px;flex-wrap:wrap;}
.hero-stats div b{display:block;font-family:var(--font-display);font-size:1.7rem;color:#fff;}
.hero-stats div span{font-size:.8rem;color:var(--slate-300);}

/* ---------- Section headings ---------- */
.section{padding:64px 0;}
.section-head{max-width:640px;margin:0 auto 40px;text-align:center;}
.section-head .kicker{
  font-family:var(--font-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;
  color:var(--indigo-600);font-weight:700;
}
.section-head h2{font-size:clamp(1.6rem,3vw,2.2rem);margin-top:8px;}
.section-head p{color:var(--slate-500);}

/* ---------- Tool grid on homepage ---------- */
.tool-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(270px,1fr));gap:20px;}
.tool-card{
  background:#fff;border:1px solid var(--slate-200);border-radius:var(--radius-lg);
  padding:26px;display:flex;flex-direction:column;gap:10px;transition:transform .18s,box-shadow .18s,border-color .18s;
  position:relative;overflow:hidden;
}
.tool-card::before{
  content:"";position:absolute;top:0;left:0;right:0;height:3px;
  background:linear-gradient(90deg,var(--indigo-500),var(--amber-500));
  transform:scaleX(0);transform-origin:left;transition:transform .25s;
}
.tool-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);border-color:var(--indigo-100);}
.tool-card:hover::before{transform:scaleX(1);}
.tool-card .icon{
  width:48px;height:48px;border-radius:12px;background:var(--indigo-50);
  display:flex;align-items:center;justify-content:center;font-size:1.5rem;
}
.tool-card h3{font-size:1.08rem;margin-bottom:2px;}
.tool-card p{color:var(--slate-500);font-size:.9rem;margin-bottom:6px;}
.tool-card .go{font-size:.85rem;font-weight:700;color:var(--indigo-600);display:inline-flex;align-items:center;gap:5px;}
.tool-card .go svg{transition:transform .15s;}
.tool-card:hover .go svg{transform:translateX(3px);}

/* ---------- Converter card (tool page) ---------- */
.tool-hero{background:linear-gradient(180deg,var(--slate-900),var(--slate-800));color:#fff;padding:44px 0 100px;}
.breadcrumbs{font-size:.82rem;color:var(--slate-300);margin-bottom:18px;}
.breadcrumbs a{color:var(--slate-300);}
.breadcrumbs a:hover{color:#fff;}
.tool-hero-inner{display:flex;align-items:center;gap:16px;}
.tool-hero .icon-big{
  width:58px;height:58px;border-radius:14px;background:rgba(255,255,255,.08);
  display:flex;align-items:center;justify-content:center;font-size:1.9rem;flex-shrink:0;
  border:1px solid rgba(255,255,255,.12);
}
.tool-hero h1{color:#fff;font-size:clamp(1.6rem,3.4vw,2.3rem);margin-bottom:6px;}
.tool-hero p{color:var(--slate-300);margin:0;max-width:600px;}

.converter-card{
  background:#fff;border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);
  padding:32px;margin-top:-64px;position:relative;z-index:5;
}
.converter-row{display:grid;grid-template-columns:1fr auto 1fr;gap:18px;align-items:end;}
.converter-field label{display:block;font-size:.78rem;font-weight:700;color:var(--slate-500);text-transform:uppercase;letter-spacing:.04em;margin-bottom:8px;}
.converter-field .field-box{display:flex;border:1.5px solid var(--slate-200);border-radius:var(--radius-md);overflow:hidden;transition:border-color .15s;}
.converter-field .field-box:focus-within{border-color:var(--indigo-500);box-shadow:0 0 0 3px var(--indigo-100);}
.converter-field input[type=number],.converter-field input[type=text]{
  border:none;padding:14px 14px;font-size:1.15rem;font-family:var(--font-mono);width:100%;min-width:0;color:var(--slate-900);
}
.converter-field input:focus{outline:none;}
.converter-field select{
  border:none;border-left:1.5px solid var(--slate-200);background:var(--slate-50);
  padding:0 12px;font-size:.92rem;font-weight:600;color:var(--slate-800);min-width:120px;font-family:var(--font-body);
}
.swap-btn{
  width:44px;height:44px;border-radius:50%;border:1.5px solid var(--slate-200);background:#fff;
  display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--indigo-600);
  transition:background .15s,transform .2s;
}
.swap-btn:hover{background:var(--indigo-50);}
.swap-btn.spin{transform:rotate(180deg);}
.converter-extra{margin-top:22px;}
.result-line{
  margin-top:22px;padding:18px;border-radius:var(--radius-md);background:var(--indigo-50);
  display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:10px;
}
.result-line .txt{font-size:.92rem;color:var(--slate-700);}
.result-line b{font-family:var(--font-mono);color:var(--indigo-700);font-size:1.05rem;}
.copy-btn{
  background:var(--indigo-600);color:#fff;border:none;padding:9px 16px;border-radius:999px;
  font-size:.82rem;font-weight:700;cursor:pointer;transition:background .15s;
}
.copy-btn:hover{background:var(--indigo-700);}
.quick-chips{display:flex;gap:8px;flex-wrap:wrap;margin-top:18px;}
.quick-chips button{
  background:var(--slate-100);border:1px solid var(--slate-200);border-radius:999px;padding:6px 14px;
  font-size:.8rem;font-weight:600;color:var(--slate-700);cursor:pointer;
}
.quick-chips button:hover{background:var(--indigo-50);border-color:var(--indigo-100);color:var(--indigo-700);}

.table-wrap{overflow-x:auto;margin-top:22px;}
table.conv-table{width:100%;border-collapse:collapse;font-size:.9rem;}
table.conv-table th,table.conv-table td{padding:10px 12px;border-bottom:1px solid var(--slate-100);text-align:left;}
table.conv-table th{color:var(--slate-500);font-size:.75rem;text-transform:uppercase;letter-spacing:.04em;}

/* ---------- Content article ---------- */
.article{max-width:760px;margin:70px auto 0;}
.article h2{font-size:1.4rem;margin-top:2em;}
.article h2:first-child{margin-top:0;}
.article p{color:var(--slate-700);}
.article ul{color:var(--slate-700);padding-left:1.2em;}
.article li{margin-bottom:.4em;}

.faq{max-width:760px;margin:50px auto 0;}
.faq-item{border-bottom:1px solid var(--slate-200);padding:18px 0;}
.faq-item summary{
  cursor:pointer;font-weight:700;color:var(--slate-900);font-family:var(--font-display);
  list-style:none;display:flex;justify-content:space-between;align-items:center;gap:10px;
}
.faq-item summary::-webkit-details-marker{display:none;}
.faq-item summary::after{content:"+";font-size:1.4rem;color:var(--indigo-500);transition:transform .2s;flex-shrink:0;}
.faq-item[open] summary::after{content:"–";}
.faq-item p{margin-top:10px;color:var(--slate-600);}

/* ---------- Related tools ---------- */
.related{margin-top:70px;}

/* ---------- Category strip ---------- */
.category-strip{background:var(--indigo-50);padding:26px 0;border-top:1px solid var(--indigo-100);border-bottom:1px solid var(--indigo-100);}
.category-strip .container{display:flex;gap:12px;overflow-x:auto;padding-bottom:4px;}
.category-strip a{
  white-space:nowrap;background:#fff;border:1px solid var(--slate-200);padding:8px 16px;border-radius:999px;
  font-size:.82rem;font-weight:600;color:var(--slate-700);
}
.category-strip a.active,.category-strip a:hover{background:var(--indigo-600);color:#fff;border-color:var(--indigo-600);}

/* ---------- CTA banner ---------- */
.cta-banner{
  background:linear-gradient(120deg,var(--indigo-700),var(--indigo-900));
  color:#fff;border-radius:var(--radius-lg);padding:44px;text-align:center;margin:60px auto 0;max-width:var(--max-w);
}
.cta-banner h2{color:#fff;}
.cta-banner p{color:var(--indigo-100);}

/* ---------- Footer ---------- */
.site-footer{background:var(--slate-950);color:var(--slate-300);padding:56px 0 26px;margin-top:80px;}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:36px;}
.footer-brand .brand{color:#fff;}
.footer-brand p{color:var(--slate-500);font-size:.88rem;margin-top:14px;max-width:280px;}
.footer-col h4{color:#fff;font-size:.85rem;text-transform:uppercase;letter-spacing:.05em;margin-bottom:16px;}
.footer-col ul{list-style:none;margin:0;padding:0;}
.footer-col li{margin-bottom:10px;}
.footer-col a{color:var(--slate-400);font-size:.9rem;}
.footer-col a:hover{color:#fff;}
.footer-bottom{
  border-top:1px solid rgba(148,163,184,.15);margin-top:44px;padding-top:22px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-size:.82rem;color:var(--slate-500);
}
.footer-bottom a{color:var(--slate-500);}
.footer-bottom a:hover{color:#fff;}

/* ---------- Static pages ---------- */
.page-hero{background:linear-gradient(180deg,var(--slate-900),var(--indigo-900));color:#fff;padding:60px 0;}
.page-hero h1{color:#fff;}
.page-hero p{color:var(--slate-300);}
.static-content{max-width:760px;margin:0 auto;padding:56px 0;color:var(--slate-700);}
.static-content h2{margin-top:1.6em;}
.contact-form{display:grid;gap:16px;max-width:520px;}
.contact-form label{font-weight:700;font-size:.85rem;color:var(--slate-700);}
.contact-form input,.contact-form textarea{
  width:100%;padding:12px 14px;border:1.5px solid var(--slate-200);border-radius:var(--radius-sm);
  font-family:var(--font-body);font-size:.95rem;margin-top:6px;
}
.contact-form button{
  background:var(--indigo-600);color:#fff;border:none;padding:13px 22px;border-radius:999px;
  font-weight:700;cursor:pointer;justify-self:start;
}
.contact-form button:hover{background:var(--indigo-700);}

/* ---------- Utility ---------- */
.badge{display:inline-block;background:var(--indigo-100);color:var(--indigo-700);font-size:.72rem;font-weight:700;padding:3px 10px;border-radius:999px;}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;}
:focus-visible{outline:2px solid var(--amber-500);outline-offset:2px;}

/* ---------- Responsive ---------- */
@media (max-width:860px){
  .main-nav{position:fixed;top:68px;left:0;right:0;background:var(--slate-900);flex-direction:column;
    align-items:flex-start;padding:18px 24px;gap:14px;display:none;border-bottom:1px solid rgba(148,163,184,.15);}
  .main-nav.open{display:flex;}
  .nav-toggle{display:block;}
  .header-search{display:none;}
  .footer-grid{grid-template-columns:1fr 1fr;}
  .converter-row{grid-template-columns:1fr;}
  .swap-btn{justify-self:center;transform:rotate(90deg);}
  .swap-btn.spin{transform:rotate(270deg);}
}
@media (max-width:520px){
  .footer-grid{grid-template-columns:1fr;}
  .hero-stats{gap:22px;}
}
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important;}
}